The need for a tool to compress heavy coil springs is well known in the art. The need for such tools has become even more important since more and more vehicles having independent suspensions are now in use. Many of these vehicles use a MacPherson type strut suspension which is particularly popular on imported vehicle because of its space saving attributes. The heavy coil springs are compressed and support a substantial part of the vehicle weight. In the after market, the independent suspensions must be serviced, particularly the shock absorber cylinder which in the MacPherson type independent suspension is located within the heavy coil spring. Often a frame hoist is used, but even when the supporting members engaged by the spring are spaced apart at their maximum distance, the heavy coil spring is often still under a load and must be compressed still further before it can be removed. Mechanical linkages have been used in the prior art to compress the heavy springs, for example the type shown in U.S. Pat. No. 1,342,529. However, many of these prior art tools have been clumsy to use and relatively inefficient.
More recently, bench type tools, for example the spring compressor shown in U.S. Pat. No. 3,814,382, have been introduced to the marketplace. However, to remove the coil spring from a vehicle and then to insert it into a bench type tool is time consuming. Manual spring compressors are often used in the initial operation. Because the heavy duty springs are helical in configuration and under load, it is not unusual for the manual tool to slip from the engaged coils of the spring.